This week's Space Cover of the Week commemorates the 24th International Astronomical Congress held in Baku, Russia October 8-12, 1973. The postmark was designed by R. Strelnikov. Catalog numbers are Winick 1636 and Pfau S-160.

The Soviet Union Ministry of Communications released just one postal item to commemorate the IAF Congress a prestamped artistic envelope with a production date of August 9, 1973 and Pfau G236 catalog number.